This invention relates to an endoscopic device, and particularly, to such a device which facilitates the placement and manipulation of a surgical knot endoscopically for tissue approximation and vessel ligation.
As medical and hospital costs continue to increase, surgeons are constantly striving to develop advanced surgical techniques. Advances in the surgical field are often related to the development of operative techniques which involve less invasive surgical procedures and reduce overall patient trauma. In this manner, the length of hospital stays can be significantly reduced, and therefore the hospital and medical costs ca be reduced as well.
One of the truly great advances in recent years to reduce the invasiveness of surgical procedures is endoscopic surgery. Endoscopic surgery involves the use of an endoscope, which is an instrument permitting the visual inspection and magnification of any cavity of the body. The endoscope is inserted through a tube, conventionally referred to as a cannula, after puncture of a hole into the soft tissue protecting the body cavity. The hole is made with a trocar, which is a sharp-pointed instrument. The trocar includes an obturator, or cutting implement, which is slideably and removably disposed within a trocar cannula. The obturator will puncture a hole in the tissue equal in size to the inner diameter of the trocar cannula. After puncture, the obturator can be slideably withdrawn from the trocar cannula. The surgeon can then perform diagnostic and therapeutic procedures at the surgical site with the aid of specialized instrumentation designed to fit through the trocar cannula and additional trocar cannulas providing openings into the desired body cavity as may be required.
In many surgical procedures, including those involving endoscopic surgery, it is often necessary to tie knots. For example, suturing to approximate tissue requires the formation of a suture knot for placement of a stitch. Additionally, ligating blood vessels to be cut within the surgical site is often necessary in numerous surgical procedures. The vessels may then be severed between the ligations. The primary reason for ligating the vessels is to maintain the surgical site free of an excess of blood and to reduce blood loss in the patient.
Conventionally, surgeons have closed blood vessels with ligatures, which are long, relatively straight strands of suture material. As is the case with the formation of a suture knot to place a stitch, the surgeon must manually tie a knot on the ligature after the ligature is looped around the vessel desired to be closed. Unfortunately, the formation of a knot on sutures and conventional ligatures is tedious and time-consuming during endoscopic surgical applications where a surgeon's manual operative techniques within the surgical site are severely restricted.
In more recent years, a ligature has been developed which is better adapted for endoscopic surgery. ENDOKNOT gut ligature is a device formed from a suture material of surgical catgut. The catgut ligature is securely fastened within a cannula at one end and attached to a needle at the other end. This device is described in the 1991 package insert for the product sold by Ethicon, Inc., which insert is entitled "ENDOKNOT Suture Made With Chromic Gut". Although ENDOKNOT gut ligature facilitates ligation of vessels through small incisions in bodily cavities, the surgeon is required to manually tie the ligature knot extracorporeally, i.e. outside the body, to ligate a vessel. This is a time consuming and laborious process, especially for inexperienced surgeons, and represents a significant disadvantage to the use of the ENDOKNOT ligature device during endoscopic surgery.
The need for manually tying the knot extracorporeally for ligation or tissue approximation was eliminated by using the device described in U.S. Pat. No. 5,144,961. This device has a partially tightened knot secured around a cannula, and the knot can be slid down the cannula onto a suture strand to make a loop which can then be subsequently tightened into a secure knot. Unfortunately, in operation the user must thread the suture strand up through the cannula before sliding the partially tightened knot down the cannula to make the loop. This threading operation is undesirable because it is time consuming and tedious. A similar device is shown in U.S. Pat. No. 2,012,776.
In view of the significant deficiency of the prior art, an endoscopic knotting device which avoids manually tying knots extracorporeally, and threading the suture strand through the cannula, would be highly desired within the medical community.